1. Field of the Invention
The present invention relates to an apparatus for applying adhesive sheets to plate-shaped materials such as substrates, semiconductor wafers and the like.
2. Description of Prior Art
When a semiconductor device is manufactured in accordance with the prior art, a semiconductor wafer is cut into separate IC chips (dicing) which are then picked up and bonded to a lead frame (die bonding). When carrying out such die bonding, an adhesive is applied to each IC chip and then a thermocompression bonding is carried out to bond the chip to the lead frame so as to form a semiconductor device.
In recent years, the heat and mechanical properties of semiconductor devices have been improved by forming a resin film on the circuit surface and underside surface of the semiconductor wafer. Various resin films have been used, with examples including seal improving films for improving the seal between the sealant resin and the underside surface of the chip, passivation films, layer insulating films, .alpha.-ray cut-off films, pattern forming films, die pad adhesive films and the like.
Further, resin films are also formed on plate-shaped materials or substrates other than semiconductor devices, with examples including liquid crystal orientation films, printed circuit board protection films, X-ray exposure masking films and the like.
These resin films can be transformed from their normal liquid state to a dried film by applying such resins by means of spin coating or the like.
However, this method of applying a resin film with a spin coater wastes material, and this leads to a lower productivity. Further, because organic solvents for diluting materials vaporize in a clean room, this results in poor working environments in the clean room. Moreover, a great deal of skill is needed to form a homogeneous resin film.